GB/T 31303-2014Austenitic-Ferritic duplex stainless steel bars (English PDF)

1 Scope

This Standard specifies the classification and code, size, shape, weight and allowable deviation, technical requirements, test methods, inspection rules, packaging, marking, and quality certificates of austenitic-ferritic duplex stainless steel bars.

This Standard applies to rolled or forged austenitic-ferritic duplex stainless steel bars with dimensions (diameter, side length, thickness or distance of the opposite side) not exceeding 250mm. Austenitic-ferritic duplex stainless steel bars (hereinafter referred to as steel bars) with dimensions (diameter, side length, thickness or distance of the opposite side) greater than 250mm can also be supplied upon negotiation between the supplier and the purchaser.

2 Normative References

The following documents are essential to the application of this Document. For the dated documents, only the versions with the dates indicated are applicable to this Document; for the undated documents, only the latest version (including all the amendments) is applicable to this Document.

GB/T 222 Permissible tolerances for chemical composition of steel products

GB/T 223.3 Methods for chemical analysis of iron, steel and alloy - The diantipyryl methane phosphomolybdate gravimetric method for the determination of phosphorus content

GB/T 223.4 Alloyed steel - Determination of manganese content - Potentiometric or visual titration method

GB/T 223.5 Steel and iron - Determination of acid-soluble silicon and total silicon content - Reduced molybdosilicate spectrophotometric method

GB/T 223.11 Iron, Steel and Alloy - Determination of Chromium Content - Visual Titration or Potentiometric Titration Method

GB/T 223.16 Methods for Chemical Analysis of Iron, Steel and Alloy - The Chromotropic Acid Photometric Method for the Determination of Titanium Content

GB/T 223.17 Methods for chemical analysis of iron steel and alloy - The diantipyrylmethane photometric method for the determination of titanium content

GB/T 2101 General provisions on acceptance, package, marking and quality certificate for profile steel

GB/T 2975 Steel and Steel Products - Location and Preparation of Test Pieces for Mechanical Testing

GB/T 4162 Forged and Rolled Steel Bars - Method for Ultrasonic Testing

GB/T 4334 Corrosion of metals and alloys - Test methods for intergranular corrosion of stainless steels

GB/T 7736 Ultrasonic inspecting method for macro-structure and imperfection of steel

GB/T 10121 Steel products-Method for magnetic particle inspection of tower sample

GB/T 10561-2005 Steel - Determination of Content of Nonmetallic Inclusions - Micrographic Method Using Standards Diagrams

GB/T 11170 Stainless steel - Determination of multi-element contents - Spark discharge atomic emission spectrometric method (Routine method)

GB/T 13305 Austenitic stainless steels - Determination of area content of the alpha-phase - Micrographic method using STANDARD diagrams

GB/T 15711 Steel Products - Method for Etch Test of Tower Sample

GB/T 17505 Steel and Steel Products - General Technical Delivery Requirements

GB/T 17897 Test of pitting corrosion resistance of stainless steels in the ferric chloride solution

GB/T 20066 Steel and Iron - Sampling and Preparation of Samples for the Determination of Chemical Composition

GB/T 20123 Steel and iron - Determination of total carbon and sulfur content Infrared absorption method after combustion in an induction furnace (routine method)

GB/T 20124 Steel and iron - Determination of nitrogen content - Thermal conductimetric method after fusion in a current of inert gas

YB/T 5293 Metallic materials - Forging test

3 Ordering Contents

The contract or order for ordering according to this Standard shall include the following contents:

a) Standard number;

b) Product name;

c) Designation;

d) Dimensions;

e) Weight;

f) The used processing method (see Clause 4);

g) Delivery status;

h) Special requirements.

4 Classification and Code

4.1 Steel bars are divided into the following two categories according to the processing method:

a) Steel for pressure processing UP

1) Hot pressure processing UHP

2) Steel for hot forging UHF

b) Steel for cutting UC

4.2 The processing method of steel bars shall be specified in the contract. If not specified, they will be supplied as steel for pressure processing.

5 Dimensions, Shape, Weight and Allowable Deviations

5.1 The dimensions, shape and allowable deviations of rolled steel bars shall comply with the provisions of GB/T 702-2008, and the specific requirements shall be specified in the contract. If not specified, Group 2 of GB/T 702-2008 shall apply.

5.2 The dimensions, shape and allowable deviations of forged steel bars shall comply with the provisions of GB/T 908-2008, and the specific requirements shall be specified in the contract. If not specified, Group 2 of GB/T 908-2008 shall apply.

5.3 The delivery length of steel bars shall usually be 2000mm~12000mm; after negotiation between the supplier and the purchaser and specified in the contract, it can also be delivered in fixed length or multiple lengths. The allowable deviation of the length of rolled steel bars is +50mm 0mm, and the allowable deviation of the length of forged steel bars is +80mm 0mm.

5.4 Steel bars are usually delivered according to actual weight.

6 Technical Requirements